Re: Making init scripts use dash

[Petter Reinholdtsen <pere@hungry.com>]

[Margarita Manterola]
> During some tests I've performed, I've found that making the init
> scripts run with dash as default shell instead of bash makes the boot
> time a 10% faster (6 seconds in a 60 second boot).

I saw (parts of) your talk at debconf on this topic, and was happy to
see the results you were getting.  Are your slides on the web
somewhere?

I was a bit surprised that parallel execution only shaved 2 seconds of
the boot, but suspect it might be because of inefficient
implementation in /etc/init.d/rc.

> To make this speed up available to everyone, we have 2 main choices:
>
> 1. Make /bin/sh point to /bin/dash

Debian-edu has been doing this since woody, to avoid bash blocking the
umount of /usr/ when nss_ldap is being used (bug #120340).  We have
not experienced any serious problems with it, and all the minor
problems we have seen have been fixed quickly.

I believe this is a fairly safe thing to do, but believe it should be
done shortly after etch releases, and not just a few months before we
freeze for etch.  There are other things we can manage before etch
releases (avoid external programs, use dynamic readahead, parallel
booting, etc), and I suggest we focus on them this summer, and switch
to dash next spring. :)

Friendly,
-- 
Petter Reinholdtsen